Well Bacteria sales have gone up overnight
While i agree Bacteria is an important factor in reef tanks I personally would find it hard to pinpoint SPS issues to it. There are so many factors that make up an ecosystem and so many factors that rely on other factors. It is easy to pick any product that someone wasn't dosing when their sps failed e.g amino's or something they weren't feeding. There are so many factors that can cause sps to die that little things can be missed or not picked up. If Bacteria is missing or not 'enough' in the tank then SPS should not do well for a certain time and then decide to die.
Definitely worth looking into some more, again a bit hard to isolate it solely but it is always good to have something else to try if you are not having success.